conventional lighting fixtures, in order to meet needs of environment to be lighted, in general include two categories of lamps: a pagoda lamp and a projecting lamp. For example, they are described in the U.S. Pat. No. 4,645,980. Both lamps are quite different and, as described, are not replaceable nor combinable. Thus, the pagoda lamp serves only for the purpose of illuminating an area on the ground, while the projecting lamp is good for illumination of an area above the ground. Another difference is that in the pagoda lamp, the light emitted is spread radially, while in the projecting lamp the light emitted is sent in one particular direction.
In order to meet the requirements of potential users, manufacturers of lighting fixtures must provide two separate types of lamp. Further more, the users, wishing to take advantage of features of the pagoda lamp and the projecting lamp, must acquire both lamps. This is costly for both the manufacturer and the user, and sometimes it would be highly desirable to provide a lamp which could be used both for smaller and larger area illumination so as light could be diffused in different directions, including areas on the ground and above the ground, i.e., to provide functions both of the pagoda lamp and the projecting lamp, in combination and separately.